1. ArrayList 转换为 String[]:
ArrayList list = new ArrayList<>();
list.add("aaa");
list.add("bbb");
String[] arrString = (String[]) list.toArray(new String[list.size()]) ;
2. String[] 转换为 ArrayList:
List<String> list = Arrays.asList(list);
3. ArrayList 转换为 String:
ArrayList list = new ArrayList<>();
list.add("aaa");
list.add("bbb");
String str = String.join(",", list);
4. String 转换为 ArrayList :
String str ="1,2,3,4,5";
ArrayList b = new ArrayList( str.split(',') ) ;
转自:https://www.cnblogs.com/steffen/p/7871990.html